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UHF circuits

  

 

Ultra High Frequency (UHF) designates the ITU Radio frequency range of electromagnetic waves between 300 MHz and 3 GHz (3,000 MHz), also known as the decimetre band or decimetre wave as the wavelengths range from one to ten decimetres (10 cm to 1 metre).
 
Radio waves with frequencies above the UHF band fall into the SHF (super high frequency) and EHF (extremely high frequency) bands, all of which fall into the microwave frequency range. Lower frequency signals fall into the VHF (very high frequency) or lower bands. See Electromagnetic spectrum and Radio spectrum for a full listing of frequency bands.
 
The main advantage of UHF transmission is the physically short wave that is produced by the high frequency. The size of transmission and reception antennas is related to the size of the radio wave. The UHF antenna is stubby and short. Smaller and less conspicuous antennas can be used with higher frequency bands.
The major disadvantage of UHF is its limited broadcast range and reception, often called line-of-sight between the TV station's transmission antenna and customer's reception antenna, as opposed to VHF's very long broadcast range and reception, which is less restricted by line of sight.
 
The majority of digital TV stations currently broadcast their over-the-air signals in the UHF band, both because VHF had been largely already filled with analog TV at the time the digital facilities were built and because of severe issues with impulse noise on digital low-VHF channels. While virtual channel numbering schemes routinely display channel numbers like "2.1" or "6.1" for individual North American terrestrial HDTV broadcasts, these are more often than not actually UHF signals. Many equipment vendors therefore use "HDTV antenna" or similar branding as all but synonymous to "UHF antenna".
 
 

Circuits




A very simple and efficiency active antenna electronic project can be designed using this electronic schematic circuit that is based on transistors. This active antenna electronic project is useful...

The following circuit is an distortion booster effect for your electric guitar. I don't know whether this circuit is really works or not, you may try this circuit with your own risk. Circuit notes:...

The intensity of the laser beam varies together with the amplitude of the sound signal. The variation within the intensity of the laser beam is converted into a ... Electronic Tachometer. Here is a...

This is the very cheap low priced circuit. This is an affordable Vhf/Uhf diode Rf switch circuit diagram. This circuit uses low-cost IN4148 diodes and exhibits about 1.5 dB insertion loss from 10 t...

UHF antenna booster can be used for better reception, especially when you're far from TV station / relay transmitter. This UHF antenna booster works in 400-850 MHz range. Here is the circuit diagra...

The post explains a 330MHz UHF FM remote control transmitter circuit.


Lets build a UHF Transmitter.


UHF bug spy transmitter receiver SET, 110 or 220 V operated, quartz controlled


UHF Transmitter or Cellular Phone Jammer (12' range) up to 2GHZ


Passive infrared Detector with UHF transmitter and receiver with Mod Cell Phone.